As with most other HF wire antennas, the higher they are, the better they
play. But, as a ham who has lived in apartments for many years knows
firsthand, the main objective is to get the rf outdoors. So, put the g5rv up
wherever you can. You will have to use a tuner anyway, so put it up and call
anybody you can hear.

Meanwhile, if you want to part with your r7, I may be interested.

Mike Duke, K5XU